This paper discusses the common heritage of the Western Balkans in connection with organized crime, which, it can be claimed, did not significantly manifest under socialism. The disintegration of the former Yugoslavia led to war, destruction, and overall increase in crime, including organized crime. The factors that especially contributed to that, besides the war, are: the transition process, the increase in the level of corruption, inefficient functioning of the state apparatus, economic decline, and trade sanctions imposed by the United Nations which resulted in a sort of semi-legal cooperation between governmental authorities and organized criminal groups in the Western Balkans. Local wars in the former Yugoslavia enabled the expansion of illegal arms trafficking, theft and smuggling of motor vehicles, and smuggling of all kinds of excise goods, especially oil and cigarettes. The trafficking of narcotics became a very lucrative and widespread activity of criminal groups, with the geo-strategic position of the Western Balkans countries being one of the contributing factors. The beginning of democratic changes in Serbia marked the commencement of the fight against organized crime. It was also the start of the creation of the legal regulatory system to counter organized crime, which involves interstate cooperation at both the regional and global level, as well as the adoption of international conventions and standards. Consequently, a special police unit for combating organized crime was established within the Serbian Ministry of Interior. The Republic of Serbia, like most countries in the region, has adopted a series of legislative measures to combat organized crime, which come from experiences of other countries that have shown good results. Specific aspects of the investigative procedure and collecting evidence of organized crime cannot be achieved using conventional methods of investigation, such as home, other premises and persons’ search warrants, temporary confiscation of items, questioning of the accused, witnesses’ hearing, etc. In these efforts the basic dilemma is the level of proportionality between security and freedom, because the methods of an undercover investigation are special methods that are used to temporarily restrict the fundamental rights and freedoms of men, for the purposes of combating complex forms of crime.